Robert H Pietrzak

The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia

Are you Robert H Pietrzak?

Claim your profile

Publications (160)751.3 Total impact

  • Robert H Pietrzak, Yen Ying Lim, David Ames, Karra Harrington, Carolina Restrepo, Ralph N Martins, Alan Rembach, Simon M Laws, Colin L Masters, Victor L Villemagne, Christopher C Rowe, Paul Maruff
    [Show abstract] [Hide abstract]
    ABSTRACT: Memory changes in preclinical Alzheimer's disease (AD) are often characterized by heterogenous trajectories. However, data regarding the nature and determinants of predominant trajectories of memory changes in preclinical AD are lacking. We analyzed data from 333 cognitively healthy older adults who participated in a multicenter prospective cohort study with baseline and 18-, 36-, and 54-month follow-up assessments. Latent growth mixture modeling revealed 3 predominant trajectories of memory change: a below average, subtly declining memory trajectory (30.9%); a below average, rapidly declining memory trajectory (3.6%); and an above average, stable memory trajectory (65.5%). Compared with the stable memory trajectory, high Αβ (relative risk ratio [RRR] = 2.1), and lower Mini-Mental State Examination (RRR = 0.6) and full-scale IQ (RRR = 0.9) scores were independently associated with the subtly declining memory trajectory; and high Αβ (RRR = 8.3), APOE ε4 carriage (RRR = 6.1), and greater subjective memory impairment (RRR = 1.2) were independently associated with the rapidly declining memory trajectory. Compared with the subtly declining memory trajectory group, APOE ε4 carriage (RRR = 8.4), and subjective memory complaints (RRR = 1.2) were associated with a rapidly declining memory trajectory. These results suggest that the preclinical phase of AD may be characterized by 2 predominant trajectories of memory decline that have common (e.g., high Αβ) and unique (e.g., APOE ε4 genotype) determinants. Published by Elsevier Inc.
    Neurobiology of aging. 12/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: While posttraumatic stress disorder (PTSD) symptoms in the recently published Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) are clustered into four factors, emerging confirmatory factor analytic studies suggest that this disorder is best characterized by seven symptom clusters, including re-experiencing, avoidance, negative affect, anhedonia, externalizing behaviors, and anxious and dysphoric arousal symptoms. To date, however, data are lacking regarding the relation between this novel model of DSM-5 PTSD symptoms and measures of clinical significance in this population (e.g., functioning). Using data from the National Health and Resilience in Veterans Study (NHRVS), a contemporary, nationally representative sample of 1484 U.S. veterans, we evaluated clinical and functional correlates of a novel 7-factor model of DSM-5 PTSD symptoms. Differential patterns of associations were observed between DSM-5 PTSD symptom clusters, and psychiatric comorbidities, suicidal ideation, hostility, and functioning and quality of life. Anhedonia symptoms, in particular, were strongly related to current depression, as well as reduced mental functioning and quality of life. Externalizing behaviors were most strongly related to hostility, supporting the convergent validity of this construct. Cross-sectional design and employment of self-report measures. These results suggest that a more refined 7-factor model of DSM-5 PTSD symptoms may provide greater specificity in understanding associations with comorbid psychopathology, suicidal ideation, and functioning and quality of life in U.S. veterans. They further suggest that prevention and treatment efforts that target distinct aspects of the PTSD phenotype may be more effective in mitigating key clinical and functional outcomes in this population. Published by Elsevier B.V.
    Journal of Affective Disorders 12/2014; 174C:522-526. · 3.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The apolipoprotein E (APOE) ɛ4 allele and high levels of beta-amyloid (Aβ) are associated with episodic memory decline and risk for Alzheimer's disease. However, there is debate about independent or interactive effects of ɛ4 on Aβ-related memory decline in healthy older adults. Healthy older adults with high Aβ burden (n = 84) enrolled in Australian Imaging, Biomarkers, and Lifestyle Study were included in this study. Cognition was measured using the computerized Cogstate Brief Battery at baseline, 18-, 36-, and 54-month follow-ups. Mini Mental State Examination and Clinical Dementia Rating scales were also administered at baseline and each follow-up timepoint. Relative to Aβ+ ɛ4 noncarriers (n = 36), Aβ+ ɛ4 carriers (n = 48) showed significantly faster decline on memory tasks, which was by convention, moderate in magnitude (d = 0.40-0.47). Aβ positivity coupled with APOE ɛ4 was associated with moderately increased decline in memory over a 54-month assessment period, suggesting that, in the preclinical stages of Alzheimer's disease, the manifestation of memory decline in older adults with high Aβ is exacerbated by the presence of APOE ɛ4. Copyright © 2015 Elsevier Inc. All rights reserved.
    Neurobiology of Aging 12/2014; · 4.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the extent to which decline in memory and working memory in beta-amyloid (Aβ) positive non-demented individuals was related to hippocampal atrophy and Aβ accumulation over 36 months. Cognitively normal older adults (CN) (n = 178) and adults with mild cognitive impairment (MCI) (n = 49) underwent positron emission tomography neuroimaging, magnetic resonance imaging, and cognitive assessments at baseline, 18- and 36-months. Relative to Aβ- CNs, Aβ+ CNs and Aβ+ MCIs showed greater rates of cognitive decline, Aβ accumulation, and hippocampal atrophy. Analysis of interrelationships between these Alzheimer's disease markers in Aβ+ CNs and MCIs indicated that rate of Aβ accumulation was associated with rate of hippocampal atrophy (β = -0.05, p = .037), which was in turn associated independently with rate of decline in memory (β = -0.03, p = .032). This suggests that Aβ accumulation precedes any neurodegeneration or clinical symptoms, and that the relationship between Aβ and cognitive decline is mediated by hippocampal atrophy. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
    Archives of Clinical Neuropsychology 12/2014; · 1.92 Impact Factor
  • Biological Psychiatry 12/2014; · 9.47 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To describe the prevalence of posttraumatic stress disorder (PTSD) and comorbid psychiatric disorders and identify correlates of PTSD in a contemporary, nationally representative sample of US veterans. Data were analyzed from Wave 1 of the National Health and Resilience in Veterans Study, a cross-sectional, retrospective, web-based survey of a population-based sample of 3,157 US veterans conducted between October and December 2011. The main outcome measure was probable lifetime PTSD, which was assessed by using a DSM-IV version of the PTSD Checklist (PCL), the PCL-Specific Stressor version. The weighted lifetime and current prevalence of probable PTSD was 8.0% (standard error [SE] = 0.48) and 4.8% (SE = 0.40), respectively. 87.0% of veterans reported exposure to at least 1 potentially traumatic event (PTE); veterans reported a mean of 3.4 (SD = 2.8) different PTE types in their lifetime. Sudden death of a loved one was the most frequently endorsed PTE (61.3%), and sexual abuse in adulthood had the highest conditional probability of PTSD (37.3%). PTSD was associated with increased odds of mood, anxiety, and substance use disorders (odds ratios [ORs] = 2.2-19.1, P values < .001); suicidal ideation (OR = 9.7, P < .001); and suicide attempts (OR = 11.8, P < .001). Psychosocial factors, including resilience, community integration, and secure attachment, were associated with decreased odds of PTSD (ORs = 0.5-0.7, P values < .05). In a nationally representative sample of US veterans, the prevalence of lifetime and current PTSD was 8.0% and 4.8%, respectively, and PTSD was associated with elevated risk for several psychiatric conditions and suicidality. Veterans reported exposure to many PTE types in addition to combat, and conditional risk for PTSD was high for noncombat-related trauma. Prevention and treatment efforts designed to bolster protective psychosocial factors may help mitigate PTSD risk in this population. © Copyright 2014 Physicians Postgraduate Press, Inc.
    The Journal of clinical psychiatry. 12/2014; 75(12):1338-46.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The current study examined contributions of post-disaster stressful life events in relation to the maintenance of WTC-related posttraumatic stress, depressive symptoms, and overall functioning among rescue, recovery, and clean-up workers who responded to the September 11, 2001 World Trade Center (WTC) terrorist attacks.Methods Participants were 18,896 WTC responders, including 8,466 police officers and 10,430 non-traditional responders (85.8% male; 86.4% Caucasian; Mage = 39.5, SD = 8.8) participating in the WTC Health Program who completed an initial examination between July, 2002 and April, 2010 and who were reassessed, on average, 2.5 years later.ResultsPath analyses were conducted to evaluate contributions of life events to the maintenance of WTC-related posttraumatic stress, depressive symptoms, and overall functioning. These analyses were stratified by police and non-traditional responder groups and adjusted for age, sex, time from 9/11 to initial visit, WTC exposures (three WTC contextual exposures: co-worker, friend, or a relative died in the disaster; co-worker, friend, or a relative injured in the disaster; and responder was exposed to the dust cloud on 9/11), and interval from initial to first follow-up visit. In both groups, WTC-related posttraumatic stress, depressive symptoms, and overall functioning were stable over the follow-up period. WTC exposures were related to these three outcomes at the initial assessment. WTC-related posttraumatic stress, depressive symptoms, and overall functioning, at the initial assessment each predicted the occurrence of post-disaster stressful life events, as measured by Disaster Supplement of the Diagnostic Interview Schedule. Post-disaster stressful life events, in turn, were associated with subsequent mental health, indicating partial mediation of the stability of observed mental health.Conclusions The present findings suggest a dynamic interplay between exposure, post-disaster stressful life events, and WTC-related posttraumatic stress, depressive symptoms, and overall functioning among WTC disaster responders.
    Journal of Psychiatric Research 11/2014; · 4.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Several revisions to the symptom clusters of posttraumatic stress disorder (PTSD) have been made in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Central to the focus of this study was the revision of PTSD’s tripartite structure in DSM-IV into four symptom clusters in DSM-5. Emerging confirmatory factor analytic (CFA) studies have suggested that DSM-5 PTSD symptoms may be best represented by one of two 6-factor models: (1) an Externalizing Behaviors model characterized by a factor which combines the irritability/anger and self-destructive/reckless behavior items; and (2) an Anhedonia model characterized by items of loss of interest, detachment, and restricted affect. The current study conducted CFAs of DSM-5 PTSD symptoms assessed using the PTSD Checklist for DSM-5 (PCL-5) in two independent and diverse trauma-exposed samples of a nationally representative sample of 1,484 U.S. veterans and a sample of 497 Midwestern U.S. university undergraduate students. Relative fits of the DSM-5 model, the DSM-5 Dysphoria model, the DSM-5 Dysphoric Arousal model, the two 6-factor models, and a newly proposed 7-factor Hybrid model, which consolidates the two 6-factor models, were evaluated. Results revealed that, in both samples, both 6-factor models provided significantly better fit than the 4-factor DSM-5 model, the DSM-5 Dysphoria model and the DSM-5 Dysphoric Arousal model. Further, the 7-factor Hybrid model, which incorporates key features of both 6-factor models and is comprised of re-experiencing, avoidance, negative affect, anhedonia, externalizing behaviors, and anxious and dysphoric arousal symptom clusters, provided superior fit to the data in both samples. Results are discussed in light of theoretical and empirical support for the latent structure of DSM-5 PTSD symptoms.
    Journal of Psychiatric Research 11/2014; · 4.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Exposure to natural disasters has been linked to a range of adverse outcomes, including mental health problems (e.g., posttraumatic stress symptoms [PTSS], depression), declines in role functioning (e.g., occupational difficulties), and physical health problems (e.g., somatic complaints). However, prior research and theory suggest that the modal postdisaster response in each of these domains is resilience, defined as low levels of symptoms or problems in a given outcome over time, with minimal elevations that are limited to the time period during the disaster and its immediate aftermath. However, the extent to which disaster survivors exhibit mental health wellness (resilience across multiple mental health conditions) or general wellness (resilience across mental health, physical health, and role functioning domains) remains unexplored. The purpose of this study was to quantify mental health and general wellness, and to examine predictors of each form of wellness, in a three-wave population-based study of Hurricane Ike survivors (N = 658). Latent class growth analysis was used to determine the frequency of resilience on four outcomes (PTSS: 74.9%; depression: 57.9%; functional impairment: 45.1%; days of poor health: 52.6%), and cross-tabulations were used to determine the frequency of mental health wellness (51.2%) and general wellness (26.1%). Significant predictors of both mental health and general wellness included lower peri-event emotional reactions and higher community-level collective efficacy; loss of sentimental possessions or pets and disaster-related financial loss were negative predictors of mental health wellness, and loss of personal property was a negative predictor of general wellness. The results suggest that studies focusing on a single postdisaster outcome may have overestimated the prevalence of mental health and general wellness, and that peri-event responses, personal property loss and collective efficacy have a cross-cutting influence across multiple domains of postdisaster functioning. Copyright © 2014 Elsevier Ltd. All rights reserved.
    Social Science [?] Medicine 11/2014; 124C:162-170. · 2.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the prevalence of DSM-5 posttraumatic stress disorder (PTSD) and factor structure of PTSD symptomatology in a nationally representative sample of US veterans and examine how PTSD symptom clusters are related to depression, anxiety, suicidal ideation, hostility, physical and mental health-related functioning, and quality of life. Data were analyzed from the National Health and Resilience in Veterans Study, a nationally representative survey of 1,484 US veterans conducted from September through October 2013. Confirmatory factor analyses were conducted to evaluate the factor structure of PTSD symptoms, and structural equation models were constructed to examine the association between PTSD symptom clusters and external correlates. 12.0% of veterans screened positive for lifetime PTSD and 5.2% for past-month PTSD. A 5-factor dysphoric arousal model and a newly proposed 6-factor model both fit the data significantly better than the 4-factor model of DSM-5. The 6-factor model fit the data best in the full sample, as well as in subsamples of female veterans and veterans with lifetime PTSD. The emotional numbing symptom cluster was more strongly related to depression (P < .001) and worse mental health-related functioning (P < .001) than other symptom clusters, while the externalizing behavior symptom cluster was more strongly related to hostility (P < .001). A total of 5.2% of US veterans screened positive for past-month DSM-5 PTSD. A 6-factor model of DSM-5 PTSD symptoms, which builds on extant models and includes a sixth externalizing behavior factor, provides the best dimensional representation of DSM-5 PTSD symptom clusters and demonstrates validity in assessing health outcomes of interest in this population. © Copyright 2014 Physicians Postgraduate Press, Inc.
    The Journal of clinical psychiatry. 11/2014;
  • Julia M Whealin, Eric Kuhn, Robert H Pietrzak
    [Show abstract] [Hide abstract]
    ABSTRACT: Despite the availability of effective mental health interventions, the vast majority of veterans with a mental disorder underutilize psychological services. Contemporary research has revealed that several factors such as low education, stigma, stoicism, lack of knowledge, and negative beliefs about mental health services are associated with veterans' underutilization of services. In this article, the authors provide an overview of factors that affect symptomatic veterans' decisions about whether to seek mental health services. Second, they describe the theory of planned behavior (Ajzen & Fishbein, 1980), a useful model for understanding mental health care seeking that can inform the development of technology-based interventions designed to increase veterans' willingness to seek psychological services. Third, the authors describe the development of Considering Professional Help, a personalized web-based tool developed by the Department of Veterans Affairs, which has been designed to promote mental health care seeking in veterans with mental health problems. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
    Psychological Services 11/2014; 11(4):486-94. · 1.08 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background High β-amyloid (Aβ) is associated with faster memory decline in healthy individuals and adults with mild cognitive impairment (MCI). However, longer prospective studies are required to determine if Aβ-related memory decline continues and whether it is associated with increased rate of disease progression. Methods Healthy controls (HCs; n = 177) and adults with MCI (n = 48) underwent neuroimaging for Aβ and cognitive assessment at baseline. Cognition was reassessed 18 and 36 months later. Results Compared with low-Aβ HCs, high-Aβ HC and MCI groups showed moderate decline in episodic and working memory over 36 months. Those with MCI with low Aβ did not show any cognitive decline. Rates of disease progression were increased in the high-Aβ HC and MCI groups. Conclusions In healthy individuals, high Aβ likely indicates that Alzheimer's disease (AD)-related neurodegeneration has begun. Once commenced, the rate of decline in cognitive function remains constant across the preclinical and prodromal stages of AD.
    Alzheimer's & dementia: the journal of the Alzheimer's Association 11/2014; · 14.48 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hidden pathway maze learning tasks (HPMLTs) have been used in neuropsychological research and practice for more than 80 years. These tasks require the use of visual and auditory task feedback signals to learn the order and direction of a pathway, typically within a grid of stepping-stones, or alleys. Hidden pathway maze learning tasks are purported to assess both visuospatial learning and executive processes. The original motivation for the HPMLT paradigm for humans was to reduce a complex tactual planning task to one in which decisions could be directly measured by discrete actions at choice points guided by visual cues. Hidden maze learning paradigms were used extensively throughout the 20th century, initially to study exploratory, anticipatory, and goal-related behavior within the context of memory research, and later as an experimental tool in neuropsychology. Computerization of HPMLTs have allowed for the measurement of different move categories according to the rule structure and ipso facto, clinically meaningful differences in memory and monitoring functions during spatial search and learning. Hidden pathway maze learning tests have been used to understand the cognitive effects of ageing, neurological disorders, and psychopharmacological challenges. We provide a review of historical antecedents relevant to contemporary applications of HPMLTs in neuropsychology. It is suggested that contemporary applications of HPMLTs could be advanced by analysis of component operations necessary for efficient performance that can inform theoretical interpretations of this class of tests in clinically meaningful terms.
    Neuropsychology Review 10/2014; · 5.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Population-based data are lacking on the prevalence and comorbidity of subsyndromal depression (SSD) and its associated risk for incident psychiatric disorders in older adults. Methods Using nationally representative data from 10,409 US adults aged 55 years and older who participated in the National Epidemiologic Survey on Alcohol and Related Conditions, we evaluated associations between lifetime SSD at Wave 1, and lifetime and incident mood, anxiety, and substance use disorders over a 3-year period. Results Some 13.8% of older adults met criteria for SSD, and 13.7% met criteria for major depressive disorder (MDD). After adjustment for sociodemographic characteristics, older adults with SSD at Wave 1 had significantly increased odds of lifetime mood (adjusted odds ratios (AORs) = 3.65–10.55), anxiety (AORs = 1.61–2.50), and any personality (AOR = 1.62) disorders. After adjustment for sociodemographic characteristics and comorbid psychiatric disorders, older adults with SSD at Wave 1 had significantly increased odds of developing new-onset MDD (AOR = 1.44, 95% confidence interval (CI) = 1.01–2.05), as well as an anxiety disorder (AOR = 1.52, 95% CI = 1.04–2.20) at Wave 2. Conclusion In addition to the 13.7% of US older adults with lifetime MDD, an additional 13.8% have lifetime SSD, which is not a formally recognized diagnosis. In addition to its high prevalence, SSD is associated with elevated rates of comorbid mood, anxiety, and personality disorders, as well as the development of a new-onset MDD and anxiety disorder. These results underscore the importance of dimensional approaches to assessing depressive symptoms in older persons, as diagnostic approaches that rely on rigorous categorical classifications may fail to identify a substantial proportion of at-risk individuals.
    International Journal of Geriatric Psychiatry 10/2014; · 3.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Posttraumatic stress disorder (PTSD) is a prevalent, chronic, and disabling anxiety disorder that may develop following exposure to a traumatic event. Despite the public health significance of PTSD, relatively little is known about the etiology or pathophysiology of this disorder, and pharmacotherapy development to date has been largely opportunistic instead of mechanism-based. Recently, an accumulating body of evidence has implicated the endocannabinoid system in the etiology of PTSD, and targets within this system are believed to be suitable for treatment development. Herein, we describe evidence from translational studies arguing for the relevance of the endocannabinoid system in the etiology of PTSD. We also show mechanisms relevant for treatment development. There is convincing evidence from multiple studies for reduced endocannabinoid availability in PTSD. Brain imaging studies show molecular adaptations with elevated cannabinoid type 1 (CB1) receptor availability in PTSD which is linked to abnormal threat processing and anxious arousal symptoms. Of particular relevance is evidence showing reduced levels of the endocannabinoid anandamide and compensatory increase of CB1 receptor availability in PTSD, and an association between increased CB1 receptor availability in the amygdala and abnormal threat processing, as well as increased severity of hyperarousal, but not dysphoric symptomatology, in trauma survivors. Given that hyperarousal symptoms are the key drivers of more disabling aspects of PTSD such as emotional numbing or suicidality, novel, mechanism-based pharmacotherapies that target this particular symptom cluster in patients with PTSD may have utility in mitigating the chronicity and morbidity of the disorder. Copyright © 2014 Elsevier Ltd. All rights reserved.
    Psychoneuroendocrinology 10/2014; · 5.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Three of the most common trauma-related mental disorders—posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and generalized anxiety disorder (GAD)—are highly comorbid and share common transdiagnostic symptom dimensions of threat (i.e., fear) and loss (i.e., dysphoria) symptomatology. However, empirical evaluation of the dimensional structure of component aspects of these disorders is lacking.Methods Using structured clinical interview data from U.S. military veterans with chronic military-related PTSD, we evaluated the transdiagnostic dimensional structure of PTSD, MDD, and GAD symptoms. We then examined the relationship between the best-fitting transdiagnostic model of these symptoms, and measures of physical and mental functioning, and life satisfaction and well-being.ResultsExploratory factor analysis revealed that a 3-factor transdiagnostic model comprised of loss (i.e., dysphoria), threat (i.e., anxious arousal, re-experiencing, and avoidance symptoms), and somatic anxiety (i.e., physiological manifestations of anxiety) symptoms provided the best representation of trauma-related PTSD, MDD, and GAD symptoms. Somatic anxiety symptoms were independently associated with physical functioning, while loss symptoms were independently associated with mental functioning and life satisfaction and well-being.LimitationsEvaluation of study aims in a relatively homogeneous sample of veterans with chronic, military-related PTSD.Conclusions Results of this study suggest that a 3-factor transdiagnostic model best characterizes the dimensional structure of PTSD, MDD, and GAD symptoms in military veterans with chronic military-related PTSD. This model evidenced external validity in demonstrating differential associations with measures of physical and mental functioning, and life satisfaction and well-being. Results provide support for emerging contemporary models of psychopathology, which emphasize transdiagnostic and dimensional conceptualizations of mental disorders. Such models may have utility in understanding the functional status of trauma survivors.
    Journal of Affective Disorders 10/2014; · 3.71 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Accumulation of β-amyloid (Aβ) in the brain is associated with memory decline in healthy individuals as a prelude to Alzheimer’s disease (AD). Genetic factors may moderate this decline. We examined the role of apolipoprotein E (ε4 carrier[ε4+], ε4 non-carrier[ε4−]) and brain-derived neurotrophic factor (BDNFVal/Val, BDNFMet) in the extent to which they moderate Aβ-related memory decline. Healthy adults (n=333, Mage=70 years) enrolled in the Australian Imaging, Biomarkers and Lifestyle study underwent Aβ neuroimaging. Neuropsychological assessments were conducted at baseline, 18-, 36- and 54-month follow-ups. Aβ positron emission tomography neuroimaging was used to classify participants as Aβ− or Aβ+. Relative to Aβ−ε4−, Aβ+ε4+ individuals showed significantly faster rates of cognitive decline over 54 months across all domains (d=0.40–1.22), while Aβ+ε4− individuals showed significantly faster decline only on verbal episodic memory (EM). There were no differences in rates of cognitive change between Aβ−ε4− and Aβ−ε4+ groups. Among Aβ+ individuals, ε4+/BDNFMet participants showed a significantly faster rate of decline on verbal and visual EM, and language over 54 months compared with ε4−/BDNFVal/Val participants (d=0.90–1.02). At least two genetic loci affect the rate of Aβ-related cognitive decline. Aβ+ε4+/BDNFMet individuals can expect to show clinically significant memory impairment after 3 years, whereas Aβ+ε4+/BDNFVal/Val individuals can expect a similar degree of impairment after 10 years. Little decline over 54 months was observed in the Aβ− and Aβ+ ε4− groups, irrespective of BDNF status. These data raise important prognostic issues in managing preclinical AD, and should be considered in designing secondary preventative clinical trials.
    Molecular Psychiatry 10/2014; · 15.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the prevalence of military sexual trauma (MST) among US veterans, identify sociodemographic and military characteristics of MST, and examine the relationships between MST and psychiatric comorbidities, functioning/quality of life, and mental health treatment utilization.
    The Journal of Clinical Psychiatry 10/2014; 75(10):e1133-9. · 5.81 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To conduct a qualitative study of older American veterans' subjective perceptions of factors that contribute to successful physical, emotional, and cognitive aging. A nationally representative sample of 2,025 veterans aged 60 or older (range: 60-96; 96.9% male, 39.4% combat veterans) participated in the National Health and Resilience in Veterans Study. Using qualitative analysis software, the authors coded responses to three open-ended questions, inductively developed categories, aggregated similar categories into factors, and grouped factors into broader themes. A total of 53, 56, and 61 categories of responses was identified in response to questions about successful physical, cognitive, and emotional aging, respectively, with 10 aggregate factors linking these categories. The most prominent theme overall was "What you do," which received 2,295, 2,210, and 1,247 mentions for each of these domains of successful aging, with health behaviors the most common factor for both successful physical and cognitive aging and social engagement the most common for successful emotional aging. The theme "Who you are" was the second-most common factor (discerned from 376, 247, and 943 total mentions, respectively), with the factors that comprise this theme-personality and explanatory style, moral compass, and emotional dispositions-more commonly endorsed for successful emotional aging. External factors such as healthcare were least commonly endorsed across all domains. Older U.S. Veterans emphasize health behaviors, social engagement, and dispositional characteristics as key determinants of successful aging. Prevention and treatment initiatives that target these potentially modifiable factors may help promote successful aging in this growing segment of the population. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.
    The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry 09/2014; · 3.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: ABSTRACT Background: While it is well known that posttraumatic stress disorder (PTSD) is characterized by heterogeneous symptom clusters, little is known about predominant typologies of PTSD symptoms in older adults. Methods: Latent profile analyses (LPAs) were employed to evaluate predominant typologies of PTSD symptoms in a sample of 164 treatment-seeking older adults with childhood war-related trauma. Multinomial logistic regressions were conducted to evaluate predictors of class membership. Results: LPAs revealed that a 3-class solution best fit the data. These included an Intermediate Disturbance class (50.0%) and two Pervasive Disturbance classes, which differed with respect to severity of avoidance symptoms (Pervasive Disturbance-Low Avoidance: 33.5%, Pervasive Disturbance-High Avoidance: 16.5%). A greater number of traumatic events predicted membership in the Pervasive Disturbance classes. The Pervasive Disturbance-Low Avoidance class had a higher level of education than the Pervasive Disturbance-High Avoidance class. Compared to the Intermediate Disturbance class, the Pervasive Disturbance classes had the highest levels of depression, anxiety and somatization symptoms. Conclusion: These results suggest that PTSD in treatment-seeking older adults may be characterized by three predominant typologies, which are differentiated by overall severity and avoidance symptoms, lifetime trauma burden, education level, and comorbid depression, anxiety, and somatization symptoms. These results underscore the importance of considering heterogeneity in the phenotypic presentation of PTSD in assessment and treatment approaches for this disorder in older adults.
    International Psychogeriatrics 09/2014; · 1.89 Impact Factor

Publication Stats

2k Citations
751.30 Total Impact Points

Institutions

  • 2014
    • The Florey Institute of Neuroscience and Mental Health
      Melbourne, Victoria, Australia
    • United States Department of Veterans Affairs
      Bedford, Massachusetts, United States
  • 2009–2014
    • Yale University
      • • Department of Diagnostic Radiology and Pediatric Diagnostic Radiology
      • • Department of Psychiatry
      New Haven, Connecticut, United States
    • Yale-New Haven Hospital
      • Department of Laboratory Medicine
      New Haven, Connecticut, United States
    • RMIT University
      Melbourne, Victoria, Australia
  • 2013
    • University of Greifswald
      • Department of Psychiatry and Psychotherapy
      Greifswald, Mecklenburg-Vorpommern, Germany
    • University of Hawaiʻi at Hilo
      Hilo, Hawaii, United States
    • University of Manitoba
      Winnipeg, Manitoba, Canada
  • 2008–2013
    • University of Melbourne
      • • Department of Psychiatry
      • • Melbourne School of Psychological Sciences
      Melbourne, Victoria, Australia
    • Alpert Medical School - Brown University
      • Department of Pediatrics
      Providence, RI, United States
  • 2011
    • Naval Health Research Center
      • Department of Warfighter Performance
      San Diego, CA, United States
    • Melbourne Institute of Technology
      Melbourne, Victoria, Australia
    • Georgetown University
      Washington, Washington, D.C., United States
  • 2006–2011
    • University of Connecticut
      • Department of Psychology
      Storrs, CT, United States
  • 2006–2008
    • UConn Health Center
      • • Division of Behavioral Sciences and Community Health
      • • Department of Psychiatry
      Farmington, CT, United States
  • 2005
    • Colby College
      Waterville, Maine, United States